CZ195094A3 - Transparent substrate being provided with a strata of thin layers and the use thereof for heat-insulating and sun glasses - Google Patents

Abstract

Transparent substrate (1), especially of glass, with thin multilayers, on which the following are deposited in succession: - a first coating of dielectric material (2), - a first layer (3) with properties of reflection in the infrared, especially metal-based, - a second coating of dielectric material (5), - a second layer (6) with properties of reflection in the infrared, especially metal-based, - a third coating of dielectric material (8), characterised in that the thickness of the first layer with properties of reflection in the infrared (3) corresponds to approximately 50 to 80 %, especially 55 to 75 % and preferably 60 to 70 %, of that of the second layer with properties of reflection in the infrared (6). <IMAGE>

Description

The invention relates to transparent substrates, in particular of glass, which are provided with a coating of layers of thin layers comprising at least one metal layer capable of acting on solar and / or infrared radiation of long wavelength. The invention also relates to the use of such substrates for the production of thermally insulating glass panes and / or for sun protection. These glass panes are intended for both buildings and vehicles, in particular in order to reduce the need for air conditioning and / or to reduce the overheating resulting from the ever-increasing proportion of glass surfaces in living spaces.

Prior art

A known layer of thin layers for imparting such properties is formed by at least one metal layer, such as a silver layer, which is sandwiched between two layers of a metal oxide type dielectric material. This layer is usually obtained by a sequence of applied coatings, realized by a cathodic process, using a vacuum and a cathodic sputtering, which is assisted by a magnetic field.

It is thus known from patent application WO 90/02653 laminated glass intended for automobiles, in which, with respect to the interior of the vehicle, the outermost glass substrate is provided with a stack of five layers on its inner surface in contact with an intermediate layer of thermoplastic material. This stack consists of two layers of silver interspersed with three layers of zinc oxide, the silver layer closest to the outer support substrate of the stack having a thickness slightly greater than the thickness of the second layer of silver.

The laminated glasses according to this application are used as

- 7. windscreen, which explains why they have very high values of light transmission T ' _L around 75%, in order to respect the applicable safety standards, so they are probably also relatively high value of the solar factor FS. It is worth mentioning here that the term solar factor of glass means the ratio between the total energy entering the room through the glass and the total

J incident solar energy.

The object of the invention is to provide a transparent substrate as a carrier of a layer of thin layers with two layers reflecting radiation in the infrared band, in particular metallic, so as to be characterized by high selectivity, i.e. the highest possible T ^ / FS ratio for a given T ^ value. while ensuring that said substrate has an aesthetically pleasing appearance in reflection.

The essence of the invention

The invention relates to a transparent substrate, in particular of glass, with several thin layers, on which a first coating of dielectric material, a first layer capable of reflecting infrared radiation, in particular on a metal basis, a second coating of dielectric material, a second layer of Infrared reflectance, in particular on a metal basis, a third coating of dielectric material, the essence of which is that the thickness of the first infrared reflective layer, i.e. the layer closest to the support substrate, corresponds to 50 to 80%, in particular 55 to 75%. preferably 60-70% drus ⁵ he layer with the ability to reflect infrared radiation. Preferably ^the example corresponds to the thickness of the first layer corresponding to approximately 65% of the second layer.

This marked asymmetry in the thickness of the layers with the ability to reflect infrared radiation makes it possible to advantageously modulate the T _L values so as to obtain glasses with good selectivity, i.

a good compromise between striving for transparency and the ability to best protect against thermal sunlight.

-3The choice of such an asymmetry also has an advantageous consequence. Not only does it allow to obtain glasses whose appearance, especially in reflection, is pleasant, ie having a neutral color, but also such an appearance remains almost unchanged regardless of the angle of incidence. When looking at the facade of a building completely glazed with such glass, the exterior does not have a visual impression of a change in color tone or shade according to the location of the facade on which the view is fixed. This homogeneity of appearance is very interesting, as it is currently sought after by architects in the construction industry.

In addition, the appearance and visual appearance of the glass, both in transmission and reflection, can also be finely varied and controlled by an appropriate choice of materials and thicknesses of the three dielectric coatings.

According to a first non-limiting variant of the invention, it is thus possible to select an optical thickness of the second coating of dielectric material approximately equal to the thickness of the third coating. Thus, the optical thickness of the second coating is preferably chosen to be greater than or equal to 110% of the sum of the optical thicknesses of the two further coatings and preferably corresponds to 110 to 120% of said sum.

Another variant concerning the relative thicknesses of the dielectric material, also advantageous, consists in choosing the optical thickness of the first coating so as to be greater than the optical thickness of the third coating. The optical thickness of the first coating can thus correspond to at least 110% of the optical thickness of the third coating, in particular at least 110 to 140% and in particular 115% to 13-5% and more preferably about 125% of the optical thickness of this coating. In this case, it is recommended to choose the optical thickness of the second coating of dielectric material approximately equal to the sum of the optical thicknesses by selecting other coatings.

In the first and second cases, they allow such relative ones

-4 the proportions between the optical thicknesses of the coating to obtain colors in reflection and also in transmission, which are appreciated from an aesthetic point of view, especially blue or green.

The second variant is further characterized by an additional advantage over the first, in that it increases the insensitivity of the stack to variations in the thickness of the various layers which make it up. This means that slight variations in the thickness of one of the layers of the stack do not result in significant defects in appearance from one glass to another or within the same glass. This is a feature that is very important on an industrial scale, where large and large series of glasses are produced in an effort to maintain the appearance and properties as homogeneous and stable as possible from one series of glasses to another and especially between zones of one and the same glass.

Regarding the choice of material for this layer of thin layers, it is recommended to deposit a thin barrier layer on each of the layers capable of reflecting infrared rays, especially of metal, especially when the dielectric coatings deposited thereon are applied by reactive sputtering in presence of oxygen. These barrier layers thus protect the metal layers against contact with oxygen by oxidizing themselves upon deposition of the upper dielectric coating. They are preferably based on a chromium-nickel alloy, titanium or tantalum, and have a thickness of 1 to 3 nanometers.

As far as infrared reflective layers are concerned, good results are obtained with silver layers.

The dielectric material coatings are in particular based on tantalum oxide, zinc oxide, tin oxide, niobium oxide, titanium oxide or a mixture of certain of these oxides. It is also possible for at least one of these coatings to in fact consist of two superimposed oxide layers, one of tin oxide and the other of an oxide which makes it possible to improve the wetting.

-5-layers with the ability to reflect infrared radiation, such as tantalum oxide or niobium oxide according to French patent application 93/01546 and European patent application 94 400

289.8, or titanium oxide.

Each of the individual oxides mentioned above has its advantages. Titanium dioxide and zinc oxide are characterized by high deposition rates when deposited by reactive sputtering, which is of industrial interest. In contrast, tantalum oxide or niobium oxide make it possible to obtain an increased durability of the layers against mechanical or chemical attack, or, in addition, they allow better wetting of the silver layers when they lie below them. Mixed oxides make it possible to reach a compromise between speed and durability, and the stacking of these oxide layers on top of each other makes it possible to match the cost of the materials and the better wettability of the silver layers.

There is also an additional advantage associated with the use of tantalum oxide. Glass provided with a layer of such a material may be blue in transmission, which is also surprising because it is both reflective and aesthetically pleasing, and which is usually achieved by transmitting a color complementary to that achieved in reflection when used. thin layers are little or not absorbent at all.

A preferred embodiment of the stack according to the invention consists in choosing a thickness of 7 to 9 nanometers for the first metal layer and a layer of 11 to 13 nanometers for the second. Likewise, the optical thickness of the first and third dielectric coatings is preferably chosen in the range from 60 to 90 nanometers, their heometric thickness being ------ from the name -v-spacing ± ~ from ^- 3 0 ~ to ~ 4 ~ 5 nanometers. The optical thickness of the second coating is chosen in the range from 140 to 170 nanometers, its geometric thickness being in particular from 70 to 80 nanometers. In this context, it is worth recalling that the optical thickness is defined in a known manner by the product of the geometric, i.e. the actual thickness and the lo-6 index of the material which forms it. Depending on the type of oxide considered, the refractive index varies from 1.9 to 2.1 for tin or tantalum dioxide and to about 2.3 for oxides of the niobium oxide type.

The substrate coated with the layer according to the invention can advantageously be incorporated into a multiple glass, in particular in the form of an insulating double glazing. In this case, the double glazing has a light transmittance of 60 to 70% and a solar factor (FS) of 0.32 to 0.42, which are properties which are completely suitable for use in construction. In addition, it preferably has an optical appearance in the external reflection almost unchanged, regardless of the angle of incidence, while the values a and b in the colorimetric system (L, a, b, c) remain unchanged, less than 3 and negative.

It can also form part of a laminated glass pane, especially with a light transmission of about 70%.

Overview of figures in the drawings

The invention is explained in more detail in the following description of exemplary embodiments with reference to the accompanying drawing, the single figure of which shows a diagram of a stack on a transparent substrate according to the invention.

Examples of embodiments of the invention

The invention will now be described by way of non-limiting examples.

It should be noted that although in the examples described below, successive coatings are applied by cathodic spraying assisted by a magnetic field, any other coating method can be used as long as it allows good control, management and control of the thicknesses to be applied. .

The substrates to which the layers are applied are 4 mm thick soda-lime glass substrates, except for the last examples 7 to 10, where the substrates have a thickness of 6 mm. In the double glazing, they are applied to a second substrate, identical to the previous one, but without a coating, by means of an air gap of 10 mm, except for the last examples 7 to 10, where the air gap is 12 mm.

The invention is illustrated in accordance with the present invention, but the actual account is taken of the actual proportions in terms of thickness in order to increase its intelligibility. There is shown the substrate 1 defined above, on which lies a layer 2 of tin dioxide or tantalum, on which lies a first layer 3 of silver, a barrier layer 4 of Ni-Cr or titanium (partially oxidized), a second layer 5 of tin dioxide or tantalum. , a second layer 6 of silver, a second barrier layer 7 identical to the previous and finally the last layer 8 of one of the same oxides.

The application device comprises at least one spray chamber provided with cathodes with targets of suitable materials, under which the substrate 1 passes successively. The conditions for applying each of the layers are as follows. Silver-based layers 3 and 6 are applied with a silver target at a pressure of 0.8 Pa in an argon atmosphere. Layers 2, 5 and 8, when based on tin oxide SnO ₂ , are applied by reactive spraying with a tin target under a pressure of 0.8 Pa and in an argon / oxygen atmosphere with 36% by volume of oxygen. In contrast, when layers 2, 5 and 8 are based on tantalum or niobium oxide, they are deposited by reactive spraying with a suitable tantalum or niobium target under a pressure of 0.8 Pa and in an argon / oxygen atmosphere with about 10% oxygen content. Layers £, 1_ Ni-Cr (or titanium) was deposited using a target of an alloy of Ni-Cr (or Ti), and still under the same pressure and Atmos - a wagon ^- argon; The energy densities of the energy displacements of the substrate 1 are adjusted in a known manner to achieve the desired layer thicknesses.

In all but the latter examples, except for layers 2, 5 and 8, it is selected as the dielectric material

-8 tantalum oxide.

EXAMPLE 1 to 5

Examples 1, 2 and 5 are comparative examples in that the layers 2 and 6 of silver have almost the same thicknesses (Example 1) or different thicknesses, but where the asymmetry is reversed with respect to that proposed according to the invention (Figures 2 and 5). ). Examples 3 and 4 illustrate the solution according to the invention.

AND

The table below gives, for each of the examples, the nature and thickness (in nanometers) of the layers of the respective stack. The barrier layers 4, 7 are designated Ni-Cr, it being understood that they are in fact partially oxidized once all the layers have been applied.

Ex. 1 TAB. 1 Ex.4 Ex. 5 Ex. 2 Ex. 3 Glass (1) - - - - - Ta ₂ 0 ₅ (2) 36.5 34.5 32 32 32 Silver (3) 10 2 8 8 12 Ni-Cr (4) 2 2 2 3 2 Ta ₂ 0 ₅ (5) 77.5 94.5 77.5 72.5 77.5 Silver (6) 11 8 12 12.5 8 Ni-Cr (7) 2 2 2 2 2 Ta ₂ 0 ₅ (8) 33.5 35 33.5 32 33.5

-4 ·

The following Table 2 gives, for each of the previous examples, the values of the light transmission T _L in percent, the solar factor FS calculated according to DIN 67507 (Appendix A 233) in percent, the values of the predominant lambda-dom-t wavelength in nanometers and the purity pt the color that is assigned to it, in percent. Likewise, the corresponding values of the light reflection R _L in percent, the predominant wavelength of the reflection lambda-dom-r and the purity in the reflection pr in percent are given here, the colorimetry measurements being carried out at perpendicular incidence. All these measurements apply to

-9substrate mounting in double glazing under lighting D _g5 .

TAB. 2

Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 ^T L 69 66 70 61 62 ......................., ______________________- _and - -----...------- j - *, .- r; -; ----- FS 4 i Z9 ... 4 2 - fi fi- Lambd a-dom-t 493 Λ Q O “X -X 498 λ n r \ z? \ j / Π c / O p.t 2 5 2 4 6

^r l 12 19 10 10 21 Lambda-dom-r 561 641 496 .487 574 p.r. 3 9 3 6 35 Further they are in below table 3 summarized values prevailing wave lambda lengths -dom-r, purity in reflection

p.r. for some of the previous examples (substrates are always mounted in double glazing), but this time measured with a perpendicular to. substrate plane 60 and 70 °.

TAB. 3 am impact ke

Ex. 1 Ex. 2 Ex. 3 Lambda-dom-r 470 569 480 p.r (60 °) 5.4 3 4.68 R _l (60 °) 19 28 20 Lambda-dom-r (70 ° ) 462 490 481 p.r. (70 °) 4.3 4 3.0 R _L (70 °) 32 39 34 Further measurements colorimetry at angles impact

Ex. 5 571

-498 0.8

0 ° and 60 ° was performed, this time in the system (L *, a *, b *), namely 2 and 3g for example, which is completely identical to example 3 except that layers 2 ^and 6. silver have been reversed, and which is therefore outside the conditions proposed by the invention.

Table 4 below rearranges the values of a and b, as well as c, called the saturation value and equal to the square root of oro oříkla-10-

the sum of squares a * and b *. TAB. 4 Ex. 2 Ex.3 Ex. 5 * and (0 °) 12.2 -0.9 -2.2 b * (0 °) 3.1 -3.1 22 * c - (0 °) 12.6 3.2 22.1 * and (60 °) -1 -0.9 -1.7 b * (60 °) 2 -3 6 * C (60 °) 2.2 3.13 6.2 Of all the above listed data can be inferred

following conclusions.

At a perpendicular angle of incidence, by supplying different thicknesses to the two layers of silver, and only by making the layer of silver closest to the substrate significantly thinner, the glasses can be made blue in reflection.

It should be noted that the glasses according to the invention, in particular when the chosen dielectric is tantalum oxide, are also blue in transmission.

Indeed, only Examples 3 and 4 have lamda-dom-r values of the order of 486 nanometers and lambda-dom-t 490 nanometers, according to Table 2.

In contrast, the glasses of Examples 1 and 5 have a shade of yellow in reflection, while in Example 2 they are in shades of red-purple.

In addition, the purity of the color in the reflection p.r. in Example 2 is close to 10% and is significantly higher than the value in Examples 3 and 4 'according to the invention. (This p.r. value is even higher for Example 5).

In addition, the glasses of Examples 3 and 4 according to the invention have a good selectivity of at least 1.6 or 1.7 with a solar factor which remains below 42% or equal to this value.

Favorable colorimetry according to the invention thus obtains ^j ^ -on account protislúhecriíhoKovániZpřišíůshýGlu ^J ^ -------------- skeXv Table 3 and 4 allow to evaluate the nature of their homogeneity in the glasses according to some of the previous examples in reflection. From Table 3 it can be deduced that the glass according to Fig. 3 retains its blue color in reflection with a lambda-dom-r value which remains almost constant around 486 at 0 ° to 481 at 70 °, while the purity of reflection also remains very low .

In contrast, the glazing of Example 1, where the silver strips have approximately the same thickness, changes from a yellow color of reflection at a perpendicular impact to a blue color and then a purple color at 60 ° and then 70 °. '

From Table 4 it can be confirmed that only Example 3 according to the invention allows to keep the same appearance in the reflection regardless of the angle of incidence, since the values a and b remain almost unchanged, as well as the saturation c *.

This is not the case with the glass of Examples 2 and 5, where the values of a * and b vary completely according to the angle of incidence. The value of a thus changes for the glass from Example 2 from a very high positive value of 12.2 at 0 ° to a negative and very low value of -1 at 60 °.

Thus, only the examples of the invention reconcile the selectivity - and - in ^{- with - the -} with the same.

EXAMPLES 6 and 7

These two examples this time no longer use tantalum oxide as the dielectric material, but tin oxide, and use either titanium (Example 6) or tin oxide to form barrier layers.

-12Ni-Cr (Example 7).

Table 5 below gives the thickness values (in nanometers) for each of the stack layers.

TAB.5

Ex.6

Ex.7

Glass (1) - Sn0 ₂ (2) 34 Silver (3) 8 You or Ni-Cr (4) 1 Sn0 ₂ (5) 77 Silver (6) 12 You or Ni-Cr (7) 1 Sn0 ₂ (8) 35

1.5

74.5

11.6 1.5

Substrates with such a coating are embedded in double glazing, as explained above. The photometric measurements, for those on double glazing, were summarized in Table 6 below (perpendicular impact measurements).

TAB. 6 Ex.6

^T L 66 FS 38 ^r l 10.4 Lambda-dom-r 511 p.r 2 * and - b *

Ex.7

9.4

484

-0.5

-1.1

These glasses, such as the glasses of Examples 3 and 4, do not show a significant change in their visual appearance in reflection, regardless of the measurement angle. In reflection, they show a color which lies rather in the area of the green hues in the case of Example 6 and rather in the area of the blue tones in the case of Example 7, which are colors which remain very neutral when very small purity values are taken into account. connected by them.

Laminated glasses which contain the substrates covered by the laminate according to the invention have the favorable colorimetry observed in the case of gmo no! ijtjbkýobRlšubs £ 'rá-ť-ůfŽLne -bo — př-i -— castania — do dvouskel.

Thus, for example, the substrate coated with the layer of the previous Example 3 was assembled with another substrate of the same type, but without a layer, using a standard 0.3 mm thick polyvinyl butyral film.

The table 7 below summarizes for this group the already explained values T _L , pt, lambda-dom-t, a * and b * concerning the appearance at the passage, as well as the corresponding values R 1, pr, lambda-dom-r, a and b concerning with the appearance when reflected from the side of the substrate provided with the stack of layers, the data being in the same units as above.

TAB. 7

T _L 70

pt 1,2 lambda-dom-t 502 a * -3,27 b * 0,52 ^R L

p.r.

lambda-dom-r *

a -------------, *

483 ~ = 2? 2

-4.4

From this table 7 it can be stated that the incorporation of the coated substrates according to the invention in the laminated glass assembly does not change their aesthetic colorimetry. The laminated glass thus obtained remains in the region of blue or green tones both during transmission and reflection.

The above Examples 3, 4 and 6 according to the invention relate to the first variant of the invention mentioned above, i.e. they respect the choice of relative thicknesses between the three oxide layers 2, 5 and 8, which is very specific and following. The thickness of layer 2 is approximately equal to the thickness of layer 8, the thickness of layer 5 of the composition is slightly greater than the sum of the thicknesses of the other two layers 2 and 8. (in these examples are formed by the same oxide).

The second variant according to the invention will now be illustrated by the following examples, in particular Example 8. In this variant, the thickness ratios between layers 2, 5 and 8 are somewhat varied, the optical thickness of layer 2 being substantially (in particular 25%) greater than layers 8_. The optical thickness of the layer 5 (or the sum of the optical thicknesses of the individual sublayers which form it) is here rather approximately equal to the sum of the optical thicknesses of the other two layers 2 and 8.

EXAMPLE 8

The substrate according to this example 8 is coated with a layer close to the layer described for example 7. Layers 2, 5 and 8 are also made of tin dioxide, but have different thicknesses.

Table 8 below provides the values of the thickness values (in nanometers) of all the layers of the stack in question.

TAB.8

Ex.8

Glass (1)

Sn0 ₂ (2)

Silver (3)

Ti or Ni-Cr (4)

1.5

-15SnO ₂ (5) 74.5

Tab.8-continued

Silver (6) 12

Ti or Ni-Cr (7) 1.5

Sn0 ₂ (8) 33

The substrate is mounted in double glazing. Photometric measurements performed on double glazing were summarized in Table 9 (perpendicular impact measurements).

TAB. 9

FS lambda-dom-t

p.r.

* a

Ex. 8 65 39

9.1

486 “0.7

-0.5

When comparing these results with the results obtained in particular with Example 7, it can be stated that identical values of T1 and FS are obtained. As for the appearance of the reflection, it also lies in blue tones, with an even more neutral color, as the purity is around 1% and the values of a and b are both considerably lower than

1. Another advantage of the stack type of Example 7 is that it allows for easier variations in the thickness of the stack layers between the individual points of the substrate without causing perceptible changes in its appearance.

When e_ta.k ___ pro-V-ádéj-í -měř-n-í — aodra zu ^- at -χ-points of the substrate according to Example 8 mounted in double glazing, it is stated that the differences in value remain completely lower than 1, ie that these are differences not perceptible to the human eye, although the layers each show local local thickness variations of +/- 4%. This is very important on an industrial scale, as it makes it easier to obtain glasses which are homogeneous at the same time, i.e. not showing local changes in appearance, and reproducible, i.e. with the same appearance from one glass to another or from one series of glasses to another. This means that for a given production line, which has its own limit in terms of performance, and especially in the conditions of regularity of the obtained layers, such a layer will prove less sensitive than others to variations in layer thickness carried by the line and will be therefore, have a fairly better optical quality.

If restrictions are placed on a given optical quality, it is possible to use a production line with less stringent conditions or a somewhat less efficient line for the same type of stack.

In addition, it can be noted that it is also advantageous on an industrial scale for the layer 5 to have a thickness approximately equal to the sum of the thicknesses of the layers 2 and 8. In this case, it is sufficient to use two targets, here of tin, for which the outputs can be adjusted. once and for all in their respective application chambers. Layer 2 is then obtained by passing the substrate under one target with adjustments allowing the application of a predetermined layer. Equally. the layer 8 is obtained by passing the substrate under the second target in an adjustment allowing to obtain a coating of adequate and again predetermined thickness. As for layer 5, it is obtained by successive passages of the substrate under each of the two targets, so that the hay of the substrate superimposes the thickness corresponding to the thickness of layer 2 (or 8) and the layer thickness corresponding to layer 8 (or 2), actually the sum of the thicknesses without having to use a third target.

EXAMPLE 9 to 12

The aim of these examples is to optimize the wettability and thus the efficiency of at least one of the silver layers. They follow the proposals according to the above-mentioned European patent application 94 400 289.2.

In the case of Examples 9 and 10, layers 2 and 8 are, as in the previous case, made of tin dioxide, but layer 5 is divided into two superimposed layers, namely. first layer

5. of tin oxide and a second layer 5 'of tantalum oxide (for example 9) or of "non-tartaric oxide" (for example ^- 10j). An underlying metal layer of Ni-Cr or tin may optionally be placed under the silver layer. .

In the case of Examples 11 and 12, there is also a layer

2. divided into two superimposed layers, namely a first layer 2 of tin dioxide and a long layer 2 'of tantalum oxide (for example 11) or of niobium oxide (for example 12). An underlying metal layer can also be placed under the 3rd silver layer.

Thus, in Examples 9 and 10, the wettability of the second layer 15 is optimized, while in the case of Examples 11 and 12, the wettability of both layers 3 and 6 is optimized.

Table 10 summarizes the thicknesses of the layers present, again in nanometers.

TAB.10 Ex.9 and 10 glass (i)

Sn0 ₂ (2) 34

Ta ₂ 0 ₅ or Nb ₂ 0 ₅ (2 ') 0

Silver (3) 8

Ni-Cr (4) 1.5

ŠňÓ ₂ ~ '(5) ~' ^Ta 2 ° 5 ^{or Ni} 2 ° 5 ( ⁵ ') ¹⁰

Silver (6) 12

Ti or Ni-Cr (7) 1.5

Sn0 ₂ (8) 33

Ex. 11 and 12

10

1.2 _

1.5

-18A slight improvement in the sun protection properties of the set of strata was noted. In addition, the use of oxides known for their hardness, such as tantalum oxide or niobium oxide, contributes to optimizing the durability of the entire assembly, in particular its mechanical durability. This increase in mechanical strength is particularly pronounced for Examples 11 and 12.

Finally, the glasses according to the invention are characterized by a good selectivity of the order of 1.70, a homogeneous appearance which is pleasing to the eye (especially blue and green in reflection and possibly also in transmission), as well as a range of light transmission values which make them suitable for use. as protective sunscreens in the building industry, in particular in the form of double glazing, the stack of thin layers preferably not being located on the surface (the surfaces are numbered by convention from the outside to the inside of the protected space).

The coated substrates according to the invention can also be expediently used for the production of laminated glasses.

Claims (16)

A transparent substrate (1), in particular of glass, with a plurality of thin layers on which a first coating (2) of dielectric material is successively deposited, the first layer (3) having a wide-ranging reflection. —From names ^— on “Base. ^- Ko = vu, a second coating (5) of dielectric material, a second layer (6) capable of reflecting infrared radiation, in particular metal based, a third coating (8) of dielectric material, characterized in that the thickness of the first layer (3) with an infrared reflectance x equivalent to 55 to 75% and preferably 60-70%, and in particular about 65% of the second infrared reflective layer (6). Transparent substrate (1) according to claim 1, characterized in that the optical thickness of the second dielectric coating (5) is greater than or equal to 110% of the sum of the optical thicknesses of the two further dielectric coating (2, 8) and preferably corresponds to 110 to 120 % of that sum. The transparent substrate (1) according to claim 1, characterized in that the optical thicknesses of the first dielectric material coating (2) and the third dielectric material coating (8) are approximately the same. Transparent substrate (1) according to claim 1, characterized in that the optical thickness of the first coating (2) of dielectric "?" % of the material is greater than the optical thickness of the third coating (8) of dielectric material, wherein the optical thickness of % of the third coating (8). Transparent substrate (1) according to claim 4, characterized in that the optical thickness of the second dielectric coating (5) is approximately equal to the sum of the optical thicknesses of the first and third dielectric coatings (2, 8). Transparent substrate (1) according to any one of claims 1 to 5, characterized in that a fine metal barrier, partially oxidized layer (4, 7), in particular based on chromium-nickel, lies on each of the infrared-reflecting layers (3, 6). alloy or titanium, and preferably having a thickness of 1 to 3 nanometers. Transparent substrate (1) according to any one of claims 1 to 6, characterized in that the infrared-reflecting layers (3, 6) are silver-based. Transparent substrate (1) according to any one of claims 1 to 7, characterized in that at least one of the three coatings (2, 5, 8) of dielectric material is based on tantalum oxide, tin oxide, zinc oxide, niobium oxide, titanium oxide or a mixture of these oxides, or consisting of a first layer of tin oxide on which a second layer of tantalum oxide, niobium oxide or titanium oxide lies. Transparent substrate (1) according to any one of claims 1 to 8, characterized in that the thickness of the first infrared reflective layer (3) is in the range of 7 to 9 nanometers. A transparent substrate (1) according to any one of claims 1 to 10. 9, characterized in that the thickness of the second infrared reflection layer (6) is between 11 and 13 nanometers. Transparent substrate (1) according to any one of claims 1 to 10, characterized in that the optical thickness of the first coating (2) and the third coating (8) of dielectric material is from 60 to 90 nanometers, u (5) is in the range of from 140 to -21170 nanometers. A laminated-glass pane comprising a substrate according to any one of claims 1 to 11 having a light transmittance of about 70% and a color outside the silane of a strip of green. hc-no & h-- · · · A multiple glass pane, in particular a double glazing unit, comprising a substrate according to any one of claims 1 to 11, characterized in that it has a light transmittance (T _L ) of from 60 to 70% and a solar factor (FS) of from 0.32 to 0 , 42. A multiple glass pane comprising a substrate according to any one of claims 1 to 11, characterized in that it has an external reflection color in blue tones and possibly also in transmission, in particular if the coatings (2, 5, 8) are of tantalum oxide. 15. A multiple pane according to claim 14, characterized in that its optical appearance in the outer reflection remains nearly the same regardless of the angle of incidence, wherein the values a 'and b * in the colorimetric system (L, a *, b *, c *) remain unchanged, less than 3 and with a negative sign. Use of a substrate according to any one of claims 1 to 11 for the production of multiple insulating glasses, such as double glazing or laminated glass panes.